International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B7. Istanbul 2004 
  
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Coral bleaching can occur due to increase in temperatures 1°-2° C 
higher than average in the warm season. Coral bleaching provides 
a direct indicator of the condition of coral reefs. In last two 
decades, incidence of mass bleaching has been increasingly 
observed (Goreau and Hayes, 1994, Goreau, et al. 1997). NOAA 
SST data have been extensively used to study the relationship 
between increase in SST and coral bleaching (NOAA, 1998, 
ICRS, 1998). It is possible to predict coral bleaching by 
monitoring SST (Strong, 1998). The wide spread coral bleaching 
observed during 1997-98 is an example of the effect of elevated 
SST. This event of bleaching on the Lakshadweep Islands, India 
was also recorded using IRS LISS III data (Fig. 8). 
Bleaching 
in 1998 
  
Fig. 8. Coral beaching seen on IRS LISS III image during 1998. 
The sea level rise is highly variable both in terms of time and 
space. Various estimates for the Indian coast vary from 0.5 to 2.2 
mm per year. It is expected that the rise in sea level will lead to 
increased erosion and habitat loss, increased salinity in estuaries, 
alter tidal range, change sediment transport and increase coastal 
- flooding. Rising levels will also increase impact of storm surges. 
The response of different ecosystems to sea level rise has been 
evaluated based on their characteristics for the Gujarat coast 
(Nayak, 1994). Small increase in sea level has potential of 
causing significant changes to small islands and low-lying coasts. 
[t seems that conservation of mangrove areas will be one of the 
important step to mitigate impact of the sea level rise (Baba and 
Nayak, 2002). 
7. COASTAL ZONE MANAGEMENT 
The management of coastal zone requires data on varied aspects 
as discussed earlier. Information exists in form of thematic maps 
as well as non-spatial format. Thus it is difficult to integrate these 
data conventionally. It is, therefore necessary to develop a 
computer-based information system composed of comprehensive 
and integrated set of data designed for decision-making. In this 
remote-sensing-based management plan, basic input about coastal 
areas is derived from remote sensing data. Integration of this 
thematic data with other secondary data would lead to 
identification of suitable sites, initial zoning, sea protection plan, 
eco-system conservation, etc. 
7.1 Brackish Water Aquaculture Site Selection 
In India, the aquaculture development started with essentially to 
provide employment in rural coastal areas as well as to increase 
the export to developing countries. Aquaculture development and 
planning require comprehensive data on land use and water 
resources. IRS LISS II data was utilised to prepare coastal land 
use maps on 1:50,000 scale along the Indian coast. These maps 
show wetland features between high and low water lines and land 
use features of the adjoining shore (up to 1.5 km from high 
waterline). The land use/wetland information has been used for 
evaluating quality of the surrounding coastal waters, as this 
information was not available in most of the cases. The spatial 
distribution of mud/tidal flat areas, which are most suitable from 
substrate condition point of view give idea about potential 
available for brackish water aquaculture. These maps have been 
used by the Central and State Fisheries departments for evaluating 
proposed sites as well as for selecting new sites and reassessing 
potential for brackish water aquaculture. These maps along with 
other engineering, biological, meteorological, socio-economic and 
infrastructure related parameters were integrated using GIS for 
evaluating site suitability (Gupta et al. 1995, 2001). Site 
evaluation is carried out to determine whether site is suitable or 
not and to appreciate about requirements to make the site suitable 
(Fi.g. 9) This procedure had ensured development for brackish 
water aquaculture with minimum damage to the ecology of the 
area. 
FIRST! 
SECOND 
THIRD 
FOURTH 
EITIH 
SEN eT 
Tue S du 
NARGOL — 
  
Fig. 9. Prioritised aquaculture sites selected based on integration 
of remote-sensing-based coastal land use and other ecological, 
engineering, infrastructure related data in GIS 
7.2 Coastal Regulation Zone 
The increasing pressure on the coastal zone due to concentration 
of population, development of industries, discharge of waste 
effluents and municipal sewage and spurt in recreational 
activities, has adversely affected the coastal environment. The 
population of coastal districts is increasing through out the coastal 
areas in the world. In India, the population on coastal regions is 
1238